In a large bowl, combine the flour, sugar, and salt. Cut in the butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs.
Add the egg and mix until combined. Gradually add the ice water, a tablespoon at a time, until the dough comes together.
Form the dough into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.
In a skillet, cook the chopped onions and bell peppers over medium heat until softened.
Add the chopped meat and cook until heated through. Stir in the raisins, olives, cumin, paprika, garlic powder, salt, and black pepper. Cook for another 2 minutes, then remove from heat and let cool.
Preheat your oven to 375°F (190°C).
On a floured surface, roll out the dough to about 1/8-inch thickness. Cut the dough into 4-inch squares or circles.
Place a spoonful of filling in the center of each dough square or circle.
Fold the dough over the filling to form a triangle or half-moon shape. Press the edges together to seal, and crimp with a fork if desired.
Place the pastelitos on a baking sheet lined with parchment paper. Brush the tops with the beaten egg.
Bake in the preheated oven for 20-25 minutes, or until golden brown and crisp.
Let the pastelitos cool slightly before serving.
Enjoy your meal!